Expansion sheath for wood-spikes



Aug. 15, 1933. R, BRoslG EXPANSION sHEATH FOR woon sPIxEs Filed Nov. 5. 1932 Patented Aug. 15, 1933 "PATENT o Fries4 y 1,922,120 EXPANSION SHEATH FOR WOOD-SPIKES Richard Brosig, Bad Charlottenbrunn, Germany Application November e, 1932, serial No. 641,059, and in Germany October 5, 193].

4 claims.

This invention relates toa sheath for Wood screw-spikes, more particularly for screw-spikes` for railroad sleepers. 4 Y

Itis ltnown that the screw-spikes which secure the chairs orthe rails to the wooden t. t Vsleepers of a railroad become gradually loosened during the `course of their normal use asthe wood fibres deteriorate owing to constant vibration and exposure to the weather. and` when 10 loosened the screw-spikes tend to rotate and thus become `disconnected from the chairs or rails.

Ithas been proposed to render the holes in the sleepers fit for further service by the use of screw or'insert plugs but the renovation of sleepers which are still serviceable,.is limited, since such sleepers can only be r'e-employed with the same superstructure and gauge of track, and it is necessary to secure Vthe screw-spikes without removing the sleepers from the track.

plugs constructed for example of wood into the holes in the sleepers but the walls of such hollow plugs are so fragile that upon the rotation of the screw-spikes therein, the said plugs fracture and the desired object is not attained.

Again it has been proposed to surround theV screw-spike with a split metal plug, but this arrangement has proved to be impracticable inasmuch as the material is rigid and the screwspikes of necessity become loosened after a short period of use owing to the vibrations to which the track is subjected.

According to this invention a sheath for a screw-spike is provided in the form vof a tube constructed of a tough 4and yielding material, for example, hard paper or papier-mch and split longitudinally so that the split edges wholly or partly overlap each other. -40 It is sufficient if the edges of the sheath oversaid sheath leaving a gap between the said edges along the lower portion thereof. The overlapping in the upper part of the sheath is desirable in order `to prevent the percolation of water `into the hole in the sleeper in which `the sheath is arranged to befitted.

To enable the invention to be fully understood reference is directed tothe accompanying drawa ing in which for a screw-spike constructed according to the invention and` Figure 2 is a sectionon` the Figure 1.

Further it has been proposed to insert hollow lap each other solely in the `upper part of the.

line II-II on,

Referring tothe drawing there is illustrated a sheath constructed, for example, `of hard paper The sheath is formed with at least one ex.

ternal projection, for example, the longitudinal ribs 3 which are arranged to prevent the sheath from turning when inserted in the hole in the sleeper and the said sheath is formed with an inner and outer screw-thread 4.

The longitudinal split in the sheath `'facilitates the introduction `thereof into the hole inthe sleeper, the said sheath being constructed of a diameter such that a slight compression of the said` sheath is necessary during the insertion` thereof, the subsequent' screwing of the screw spike-within the said sheath expanding itso that it is nrmly pressed against the wall of the hole in the sleeper.

An advantage attained by the use of the matei rial referred to above, consists in that the friction between the external screw-threads of the screw-spike and the sheath isgreater than that which is possible when the known split metal ktube is employed.

` If the upper part of the hole in the sleeper` threaded tube constructed of tough and yielding material, split longitudinally, the split edges thereof overlapping one another only -for a por:- tion of the length thereof at the upper end of the tube whereby water is prevented from per-4 A colating into the hole that receives the sheath when a `screw-spike is screwedfinto position.

2. A sheath for railroad screw-spikes which comprises an,` internally and externally screwthreaded tube constructed of papier-mch, splits` longitudinally, the split edges thereof overlap` ping one another only for `a portion of theA length thereofat the upper end of. the tube whereby water is prevented from percolating into the hole that receives the sheath whenra screwil spike is screwed into position.

3. A `sheath for wood railroad screw-spikes which comprises an internally and externally screw-threaded tube constructed of tough and screw-threaded tube constructed of papiermach, split longitudinally, the said split edges thereof overlapping one another only for a portion of the length thereof at the upper end of the tube, and wherein the tube is constructed at the upper end thereof of a diameter larger relatively than the remainder ofthe tube, and is Vprovided With'y at least Vone external projection arranged in the direction of the axis of the tube.

RICHARD BROSIG.

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